The Pinnacles at Mulu National Park are a collection of 45 metre high, limestone needles that cling to the side of Gunung Api (Fire Mountain) forming a forest of silver-grey stone encircled by thick green vegetation. The trek to the Pinnacle Summit Trek is a tough and challenging one and takes 4 - 5 hours for the "Not So Fit".

The trail is only 2.4 km in length but rises some 1,200 metres. Vegetations vary following the changes of altitudes.